Apparatus for fluidizing fireextinguishing dry chemicals



A. a GUISE ETAL 2,651,373

EXTINGUIS HING DRY CHEMICALS Sept. 8, 1953 APPARATUS FOR FLUIDIZING FIRE Filed Jah. 31, 1951 F/Gi/ INVENTORS.

ARTH 8.60/55 8 4 BY/MROLD I? 9014 UR su/vsr W store the dry Patented Sept. 8, 1953 APPARATUS FOR FLUIDIZING FIRE- EXTINGUISHING DRY CHEMICALS Arthur B. Guise and Harold P. Sunstrom, Marinette, Wis., assignors to Ansul Chemical Com- P consin Marinette, Wis., a corporation of Wis- Application January 31, 1951, Serial No. 208,821

4 Claims.

This invention relates to dry chemical fireextinguishing apparatus and method for fluidizing or aerating powdered dry chemical. More specifically, the invention relates to a storage container for powdered fire-extinguishing dry chemical provided with a gas inlet tube having a construction for rapidly fiuidizing and pressurizing the store dry chemical so that it may be effectively ejected in a stream from the storage container for fire-extinguishing purposes while the ratio of dry chemical to gas in the stream remains substantially unaltered.

Dry chemical fire extinguishers usually comprise a storage container for storing powdered dry chemical which is a composition containing essentially sodium bicarbonate, as disclosed in Patent 1,793,420 February 17, 1931. Since the powdered sodium bicarbonate absorbs moisture which will cause it to cake, it is necessary to chemical in a container which is sealed against entry of moisture therein. The storage container is connected to a suitable source of gas pressure, such as cylinders of compressed carbon dioxide, nitrogen, or air which when released within aerate the dry chemical and expel the fluidized powdered dry chemical under pressure through an outlet provided in the storage chamber which may be connected to a pipe or hose for conveying the stream of dry chemical to the location where a fire is to be extinguished.

It is obviously necessary that the dry chemical in the storage container should be instantly and completely fluidized or aerated as soon as gas pressure is introduced therein so that a fluidized stream of dry chemical under pressure is instantly ejected from the storage container when needed to extinguish a fire. When large sized storage tanks are used it has been found difficult in utilizing prior constructions to build up the pressure at the top and bottom zones of the container at substantially the same rate so that the gas introduced into the container will fluidize the dry chemical and pressurize all portions of the storage container at substantially the same rate. In such constructions attempts have beenmade to secure fluidization of the dry chemical in a storage container by positioning the outlet of the gas supply adjacent the bottom of the storage tank in conjunction with specific funnel constructions, as shown in Patents 1,790,231 January 2'7, 1931, and 1,894,761 January' 17, 1933. However, such constructions did not ensure adequate fluidization and pressurization in the dry chemical storage container.

the storage chamber will fluidize or According to the present invention, the aforementioned difiiculties are overcome by providing a tube within the storage container through which gas under pressure is introduced which terminates in a nozzle head of a specific construction to evenly distribute the gas pressure within the storage container and fluidize the dry chemical therein. Further advantages and details of the invention will be apparent from the following specification and appended drawings, wherein Figure '1 is a vertical partial sectional view of a fire-extinguishing dry chemical storage container,

Figure 2 is an enlarged perspective view of a gas nozzle head shown in Figure 1,

Figure 3 is an enlarged perspective view of another type of gas nozzle head, and

Figure 4 is a perspective view of still another type of gas nozzle head.

Referring to the drawings, numeral l0 indicates a cylindrical metal storage container for storing for example lbs. powdered dry chemical therein to approximately the level indicated by numeral 12, leaving a relatively small space 25 above the top level l2 of the dry chemical. Container I0 is provided with a gas inlet opening 21 to which is connected an internally positioned gas supply tube l6 extending into the interior of the container toward the bottom thereof and terminating at about the height from the bottom of the container H] which is about one-third of the total depth of the container, as indicated by height A in Figure 1.

Container I0 is provided with removable closure cap -H which can be opened to refill the container witha fresh supply of dry chemical. The container has a smooth concave bottom surface merging with the vertical walls thereof. The bottom of the container is supported on a base l5 and is also provided with an outlet I4 from which the fluidized dry-chemical contained therein is expelled under pressure to a suitable hose connected thereto for fire-extinguishing purposes. If desired the container may be spherical or of any other suitable shape.

The bottom of gas inlet tube 16 preferably terminates at a distance of 1', where r is the radius, from the vertical axis of the cylindrical or spherical storage container and is provided with a substantially cylindrical nozzle head I1, as shown in Figure 2, or a substantially cylindrical nozzle head 22, as shown in Figure 3. Nozzle head I! has a circular orifice 18 located in its bottom face Ila. substantially aligned with the longitudinal axis of tube It to emit a gas stream therefrom downwardly and substantially parallel with the vertical axis of the storage container. Instead of a single orifice [8, a plurality of orifices 30 may be provided in the bottom face of the nozzle head, as shown in Figure 4. The nozzle head is also preferably provided with a plurality of evenly spaced circular ports 20 located in the cylindrical body portion Nb of the nozzle head to emit a plurality of gas streams substantially radially of the storage container and substantially at right angles to the gas stream emitted from port 18. However, if desired the circular ports 20 may be omitted entirely.

A modified construction of the nozzle head is illustrated in Figure 3, wherein the bottom face l'l-a of nozzle head 22 is imperforate and has radial ports 20' uniformly spaced in the nozzle body portion l'lb.

In operation, container ID, being substantially filled with powdered dry chemical, is suitably connected at its inlet 2| to a supply of compressed gas, for example nitrogen, at about 2000 lbs. per square inch pressure. The gas escapes from the nozzle head I1 through the orifices l8 and 20, as previously described, impinging against the walls of the container and forcing a path through the dry chemical to the top of the container thereby fluidizing the dry chemical and pressurizing the container in all portions thereof at substantially the same rate until an internal pressure of about 200 to about 250- lbs. per square inch is established. As a result of locating the nozzle head I! in the position within the container as previously described, the pressure developed at the top and bottom regions within the container are substantially equal. The size and number of the radial ports 28 is such as to emit therefrom a major portion of the gas fed to tube l6 and only a relatively smaller portion of gas through the axial port l8. The openings of all the ports are also adjusted so as to obtain the cross-sectional area which provide desired pressurizing time. As additional gas under pressure is supplied to container [0, the pressure within the container will be maintained at the desired pressure to expel the fluidized dry chemical in the container.

The present dry chemical storage container will supply a stream of dry chemical from outlet [4 which will have a substantially uniform ratio of dry chemical to gas in the expellant stream and the expellant stream will not be diluted with expelling gas beyond a desired predetermined maximum dilution. The present construction thus prevents an excess of pressurizing gas from entering the expelled dry chemical stream which will unbalance the desired proportions of dry chemical to gas in theme-extinguishing stream.

It is to be understood that changes and modifications may be made in the details of the invention as previously described which are intended to be included within the scope of the appended claims.

We claim:

1. A container for powdered fire-extinguishin dry chemical comprising a gas inlet tube for supplying fluidizing and pressurizing gas within said container, said inlet tube terminating short of the bottom of said container at a height therefrom of about one-third of the total depth of said container and about one-half the radial distance from the vertical axis of said container to supply gas for fiuidizing substantially the entire dry chemical content in said container and to pressurize the top and bottom zones of said container at about substantially the same rate, said inlet tube being provided with a nozzle head comprising a plurality of spaced orifices positioned radially of said inlet tube.

2. A container for powdered fire-extinguishing dry chemical comprising a gas inlet tube for supplying fluidizing and pressurizing gas within said container, said inlet tube terminating short of the bottom of said container at a height therefrom of about one-third of the total depth of said container and about one-half the radial distance from the vertical axis of said container to supply gas for fluidizing substantially the entire dry chemical content in said container and to pressurize the top and bottom zones of said container at about substantially the same rate, said inlet tube being provided with a nozzle head comprising an axial orifice in alignment with the longitudinal axis of said inlet tube and a plurality of spaced radial orifices positioned at substantially right angles to said axial orifice.

3. A container for powdered fire-extinguishing dry chemical comprising a gas inlet tube for supplying fluidizing and pressurizing gas within said container, said inlet tube terminating short of the bottom of said container at a height therefrom of about one-third of the total depth of said container and about one-half the radial distance from the vertical axis of said container to supply gas for fluidizing substantially the entire dry chemical content in said container and to pressurize the top and bottom zones of said container at about substantially the same rate, said inlet tube being provided with a nozzle head comprising a cylindrical body portion and a fiat bottom face, a plurality of orifices in the bottom face of said nozzle head and a plurality of spaced radial orifices in the said body portion positioned at substantially right angles to the orifices in the bottom face. 7

4. A container for powdered fire-extinguishing dry chemical comprising a gas inlet tube for supplying fluidizing and pressurizing gas within said container, said inlet tube terminating short of i the bottom of said container at a height therefrom of about one-third of the total depth of said container and about one-half the radial dis tance from the vertical axis of said container to supply gas for fluidizing substantially the entire dry chemical content in said container and to pressurize the top and bottom zones of said container at about substantially the same rate, said inlet tube being provided with a nozzle head comprising an axial orifice in substantial alignment with the longitudinal axis of said inlet tube and a plurality of spaced radial orifices positioned at substantially right angles to said axial orifice, the total cross-sectional area of said orifices being substantially equal in cross-sectional area to that of said inlet tube.

ARTHUR B. GUISE. 

